1. Field of the Invention
The present invention relates to an engine start switch, and particularly, to an engine start switch in which the number of components is decreased and assembly is simple.
2. Description of the Related Art
A system referred to as a keyless entry system is widely spread, which can perform locking or unlocking of a door in a vehicle or a vehicle operation such as starting and stopping of an engine using wireless communication between an on-board communication device mounted on the vehicle and a portable machine (hereinafter, abbreviated as an electronic key) referred to as an electronic key without using a mechanical type key.
In the keyless entry system, a radio signal (hereinafter, abbreviated as a request signal) referred to as a request signal is sent from the on-board communication device to the electronic key, and a radio signal (hereinafter, abbreviated as a response signal) referred to as a response signal corresponding to the request signal is sent from the electronic key to the on-board communication device.
In addition, authentication is performed based on the response signal which is received by the on-board communication device, and when the authentication is established, the above-described vehicle operation is permitted. For example, it is possible to start or stop the engine by operating an engine start switch which is disposed in the cabin of a vehicle.
In recent years, when a battery of the electronic key side is consumed and the response signal is not sent from the electronic key, as the engine start switch used in the keyless entry system, an engine start switch is in practical use, which includes a coil antenna capable of outputting drive radio waves generating an electromotive force for driving the circuit of the electronic key side when the electronic key is held in the vicinity of the engine start switch.
A technology with respect to the engine start switch is disclosed in U.S. Pat. No. 8,810,363. FIG. 9 is an exploded perspective view showing a configuration of a start and stop switch device 101 (engine start switch) according to U.S. Pat. No. 8,810,363.
The start and stop switch device 101 performs collation (authentication) of an ID code (ID information) using wireless communication between a vehicle and a portable machine (electronic key), and is used as an ignition switch of a smart ignition system (keyless entry system) which starts an engine by operating an ignition switch when the collation is established.
As shown in FIG. 9, the start and stop switch device 101 includes a switch unit 158, a push button 159, a coil antenna 160, an antenna case member 166, a circuit substrate 173, a lid member 176, and a garnish 184 (cover member).
The antenna case member 166 includes a switch accommodating portion 169, a cylindrical portion 167 and a flange portion 168 which are formed on the front side of the switch accommodating portion 169, and a substrate accommodating portion 170 which is formed on the rear side of the switch accommodating portion 169. The switch unit 158 is accommodated in the switch accommodating portion 169, the coil antenna 160 is accommodated inside the cylindrical portion 167, and the circuit substrate 173 is accommodated in the substrate accommodating portion 170.
In addition, the push button 159 is disposed to cover the outer circumferential portion of the cylindrical portion 167, and the garnish 184 (cover member) is disposed to cover the outer circumferential portion of the push button 159. Moreover, the lid member 176 is disposed to cover the rear side of the circuit substrate 173.
The push button 159 receives a rearward pressing operation. The switch unit 158 switches a switching mode (a connection state or the like of the circuit) corresponding to the pressing operation with respect to the push button 159.
The coil antenna 160 includes a cylindrical bobbin 164, and a coil 120 which is formed by winding a wire around the outer circumferential portion of the bobbin 164. Both end portions of the coil 120 are connected to the circuit substrate 173 via a terminal 165 which is a wiring member. An electronic component is mounted on the circuit substrate 173, and generates electric signals becoming transponder drive radio waves (drive radio waves). In addition, the coil antenna 160 outputs (radiates the electric signals forward) the electric signals generated by the circuit substrate 173 as the transponder drive radio waves. The circuit substrate 173 is connected to an external circuit (not shown) via a wire (not shown) which extends to the outside through an opening portion 177 formed on the lid member 176.
The start and stop switch device 101 is configured as above. In addition, when the battery of the portable machine side is consumed and the radio signals is not sent from the portable machine, if the portable machine is held in the vicinity of the start and stop switch device 101, the coil antenna 160 outputs the transponder drive radio waves toward the portable machine. In addition, on the portable machine side, it is possible to generate an electromotive force for driving a transponder (response circuit) using the transponder drive radio waves.